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Poster: Jonathan Aizen Date: Mar 2, 2004 4:20pm
Forum: movies Subject: Re: Out of Sync Videos

You can have access to the FTP site (just follow the Download Options link). We cannot give you upload privileges for production servers though. If you fix the files, upload them to your upload directory and I will move them into place.

Not sure why the audio is out of sync - the conversion tools seem to work on about 99% of the movies we get, so perhaps it has to do with your original encoding.

Jon

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Poster: kcmule Date: Mar 3, 2004 3:57pm
Forum: movies Subject: Re: Out of Sync Videos

thanks for the reply!

the FAQ mentions that flasKMPEG and VirtualDub are used to convert MPEG-2 to MPEG-4. but as far as i can tell neither of these programs can be used to create .mp4 files, like the ones i see in my ftp directory. which program do you use?

once i'm able to create the mp4 files are these the parameters i should target? (again from faq page):

MPEG-4 (big) -- 900Kbps VBR 320x240 29.97 fps progressive video with 64Kbps AAC audio. Hinted for streaming.
MPEG-4 (small) -- 250Kbps VBR 160x120 29.97 fps progressive with 64Kbps AAC audio. Hinted for streaming.

thanks for your help!,

craig

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Poster: hans-jürgen Date: May 21, 2004 9:08pm
Forum: movies Subject: Re: Out of Sync Videos

kcmule wrote:

> the FAQ mentions that flasKMPEG and VirtualDub
> are used to convert MPEG-2 to MPEG-4. but as
> far as i can tell neither of these programs can
> be used to create .mp4 files, like the ones i
> see in my ftp directory. which program do you
> use?

It seems the FAQ has been changed in the meantime, but you were right, because those two editors are not able to multiplex MPEG-4 video and AAC audio into the MP4 container. They can only handle the AVI container, i.e. with MPEG-4 video plus MP3, AC3 or PCM audio.

Anyhow, now QuickTime 6.x and mpegable (probably X4Live) are used, but still seem to cause synch problems. Normally they should be able to do this, but e.g. QT has to do all the editing in the MOV format and then pass-through to MP4 and hint the tracks as the last step. I don't know why mpegable fails though.

The FAQ also asks for a Linux converter, so I would suggest to have a look at the open source MPEG4IP project and its tools and documentation. They have converters for MPEG-anything to raw video, codecs for encoding to MPEG-4 video and AAC audio, a file muxer and a script that handles all this in one step (so they say...) called mp4encode, as far as I remember. Furthermore their live-streaming app called mp4live could also be used for creating MP4 files instead of sending a bitstream to a server.

Other Linux players/transcoders that can handle MPEG-4 content (remember, this normally means AAC audio or at least MP3) are VLC, mplayer, Xine and others. A list can be found at: http://www.audiocoding.com/wiki/index.php?page=Software+Audio+Players+for+Linux/BSD and also http://www.audiocoding.com/wiki/index.php?page=MPEG-4+Players

The brand-new v0.7.2 of VLC now includes FAAC, the open source AAC codec that is necessary to create compatible MP4 files with its transcoding option, so you don't have to compile VLC yourself with FAAC support anymore (at least the Mac OS X binary, probably the Windows binary, too, and maybe also the Linux version).

It's quite likely that mplayer could also be used for direct transcoding from MPEG-2 to MPEG-4 now, see e.g. this thread on Doom9.org: http://forum.doom9.org/showthread.php?s=&threadid=75222

> once i'm able to create the mp4 files are these
> the parameters i should target? (again from faq
> page):
>
> MPEG-4 (big) -- 900Kbps VBR 320x240 29.97 fps
> progressive video with 64Kbps AAC audio. Hinted
> for streaming.

In my opinion 64 kbps is a little bit too low for a good sound quality if you are using the normal AAC Low Complexity Profile (which FAAC and QuickTime do) and if this bitrate is meant for two channels, not mono. I would rather suggest to use ~96 kbps/stereo, either at CBR or VBR like FAAC does it. See another thread for recommended 5.1 settings with FAAC here: http://forum.doom9.org/showthread.php?s=&threadid=74708

It would be possible to obtain a high quality with the HE AAC Profile at 64 kbps/stereo, but at the moment there is only Nero 6 / Nero Digital that is able to use it. QuickTime will not be able to decode it (only the backward-compatible LC part without high frequencies), so you can only use players with plugins that can decode HE AAC. This would include Winamp (with the Audiocoding.com in_mp4.dll), WMP 6.x-9 with 3ivx DS filters and RealPlayer 10.

The hinting with all of these applications might have to be done separately with mp4creator though, the file muxer of the MPEG4IP project, because it's not sure if they implemented this capability in their own MP4 file muxers. And optimizing the resulting files in the end is also necessary, by the way. Then video and audio should be in sync throughout the whole file.

This post was modified by hans-jürgen on 2004-05-22 04:08:17

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Poster: kcmule Date: Jun 14, 2004 9:47am
Forum: movies Subject: Re: Out of Sync Videos

phew... well i can follow most of what you are saying but being an amateur, and a Windows user, i'm starting to feel a bit out of my league.
if you guys ever change your rendering software or feel like taking another crack at creating files that will play in synchronization, feel free to upload the changed files to your ftp site. i'd really appreciate any assistance you could provide. with over 600 downloads and counting it seems like users are taking advantage of the one good file that is available (mpeg2), but it would be nice if we could have files more appropriate for phone modem users also.

regards,
craig

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Poster: hans-jürgen Date: Jun 14, 2004 2:14pm
Forum: movies Subject: Re: Out of Sync Videos

> phew... well i can follow most of what you are
> saying but being an amateur, and a Windows user,
> i'm starting to feel a bit out of my league.

Sorry, I didn't mean to scare you off with all the Linux stuff. I only mentioned it, because there is a remark in the FAQ that the Internet Archive is looking for Linux tools to do the MP4 converting.

Most of the important tools from the MPEG4IP project are also available as Windows compiles, e.g. the file muxer mp4creator. There is even a GUI application that is based on this command line tool called mp4UI. Other file muxers are MP4Box from the GPAC project (command line only), the 3ivx DirectShow filter suite (needs GraphEdit to work) and the IBM Toolkit for MPEG-4 (needs an installed Java VM).

Normally all of them can create MP4 files that are in sync, because this container can handle variable bitrates in video and audio tracks fine unlike older container formats like AVI.

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Poster: kcmule Date: Mar 5, 2004 7:46am
Forum: movies Subject: Re: Out of Sync Videos

I deinterlaced the MPEG2 file before I uploaded it. I wouldn't think so, but could this be why the mp4 files got created out of sync?